A conventional combustible gas turbine engine includes a compressor, a combustor, and a turbine. The compressor compresses ambient air. The combustor combines the compressed air with a fuel and ignites the mixture creating combustion products defining a working gas. The working gas travels to the turbine. Within the turbine are a series of rows of stationary vanes and rotating blades. Each pair of rows of vanes and blades is called a stage. Typically, there are four stages in a turbine. The rotating blades are coupled to a shaft and disc assembly. As the working gas expands through the turbine, the working gas causes the blades, and therefore the shaft and disc assembly, to rotate.
It is known to provide an outer air seal structure positioned about and adjacent a row of blades in a gas turbine. One such outer air seal structure is disclosed in U.S. Pat. No. 7,033,138 B2, the disclosure of which is incorporated herein by reference. The seal structure comprises a plurality of cooling conduits defining paths through which cooling air passes from a top surface of the seal structure to outer edges of the seal structure. The cooling air functions to cool the seal structure as it passes through the cooling conduits.
It would be advantageous to provide a seal structure which allows for improved cooling of the seal structure.